Intracranial internal carotid artery calcification is not predictive of future cognitive decline

Arterial calcification in the heart-brain axis and cognitive performance over time

BACKGROUND

While cross-sectional studies suggest a link between arteriosclerosis and cognition, longitudinal research is lacking. We investigated how arteriosclerosis in the heart-brain axis is related to cognitive performance trajectories over time.

METHODS

Within the population-based Rotterdam Study, 2368 participants underwent noncontrast CT to quantify arterial calcification, a hallmark of arteriosclerosis, in five major arteries in the heart-brain axis. Following this scan, participants underwent repeated cognitive testing. The association between baseline calcification and longitudinal cognitive test performance was investigated using mixed models.

RESULTS

Higher calcification was associated with worse baseline cognitive performance across domains (e.g., β for global cognition per 10-percentile increase of intracranial carotid artery calcification: -0.01 [95% confidence interval (CI): -0.03, -0.00]). Cognition declined faster across all cognitive tests, specifically for the intracranial carotid artery (p ≤ 0.001).

DISCUSSION

Arterial calcification is associated with accelerated cognitive decline across domains, especially for arteries closer to the brain. This effect may be attributable to hemodynamic changes preceding neurovascular damage.

HIGHLIGHTS

Arterial calcification is related to accelerated cognitive decline. Arterial calcification closer to the brain exerts the most influence on cognitive decline. Vascular damage influences cognitive decline across various domains.

Intracranial arteriosclerosis is not associated with cerebral amyloid deposition

BACKGROUND

Intracranial arteriosclerosis and cerebral amyloid beta (Aβ) are both involved in the etiology of Alzheimer's disease (AD) dementia, but the direct link between these two pathologies remains elusive.

METHODS

In 633 participants (mean age 69 years, 51% women) from the population-based Rotterdam Study, we quantified cerebral Aβ accumulation on amyloid positron emission tomography (PET). We assessed calcification of the intracranial internal carotid (ICAC) and vertebrobasilar arteries (VBAC) as proxies of arteriosclerosis on non-enhanced computed tomography (CT). Using logistic and linear regression, we studied the relationship of presence, burden, and type of calcification with the presence and burden of Aβ.

RESULTS

We found no associations of ICAC [odds ratio (OR): 0.85, 95% confidence interval (CI): 0.43, 1.72] or VBAC [OR: 0.59, CI: 0.26, 1.24] with cerebral Aβ. The results did not vary across ICAC subtypes.

DISCUSSION

Intracranial arteriosclerosis was not associated with cerebral Aβ, underscoring their independence in the etiology of AD dementia.

Highlights

Comprehensive assessment of intracranial arteriosclerosis (e.g., including subtypes).Intracranial arteriosclerosis in different arteries and cerebral Aβ are not related.Arteriosclerosis and Aβ likely influence Alzheimer's disease dementia independently.

Intracranial Atherosclerotic Disease and Incident Dementia: The ARIC Study (Atherosclerosis Risk in Communities)

BACKGROUND

Studies of the neurovascular contribution to dementia have largely focused on cerebral small vessel disease (CSVD), but the role of intracranial atherosclerotic disease (ICAD) remains unknown in the general population. The objective of this study was to determine the risk of incident dementia from ICAD after adjusting for CSVD and cardiovascular risk factors in a US community-based cohort.

METHODS

We acquired brain magnetic resonance imaging examinations from 2011 through 2013 in 1980 Black and White participants in the ARIC study (Atherosclerosis Risk in Communities), a prospective cohort conducted in 4 US communities. Magnetic resonance imaging examinations included high-resolution vessel wall magnetic resonance imaging and magnetic resonance angiography to identify ICAD. Of these participants, 1590 without dementia, without missing covariates, and with adequate magnetic resonance image quality were followed through 2019 for incident dementia. Associations between ICAD and incident dementia were assessed using Cox proportional hazard ratios adjusted for CSVD (characterized by white matter hyperintensities, lacunar infarctions, and microhemorrhages), APOE4 genotype (apolipoprotein E gene ε4), and cardiovascular risk factors.

RESULTS

The mean age (SD) of study participants was 77.4 (5.2) years. ICAD was detected in 34.6% of participants. After a median follow-up of 5.6 years, 286 participants developed dementia. Compared with participants without ICAD, the fully adjusted hazard ratios (95% CIs) for incident dementia in participants with any ICAD, with ICAD only causing stenosis ≤50%, and with ICAD causing stenosis >50% in ≥1 vessel were 1.57 (1.17-2.11), 1.41 (1.02-1.95), and 1.94 (1.32-2.84), respectively. ICAD was associated with dementia even among participants with low white matter hyperintensities burden, a marker of CSVD.

CONCLUSIONS

ICAD was associated with an increased risk of incident dementia, independent of CSVD, APOE4 genotype, and cardiovascular risk factors. The increased risk of dementia was evident even among participants with low CSVD burden, a group less likely to be affected by vascular dementia, and in participants with ICAD causing only low-grade stenosis. Our results suggest that ICAD may partially mediate the effect that cardiovascular risk factors have on the brain leading to dementia. Both ICAD and CSVD must be considered to understand the vascular contributions to cognitive decline.

Intracranial Atherosclerosis Disease Associated With Cognitive Impairment and Dementia: Systematic Review and Meta-Analysis

BACKGROUND

Intracranial atherosclerosis disease (ICAD) alters cerebrovascular hemodynamics and brain structural integrity. Multiple studies have evaluated the link between ICAD and cognitive impairment, with mixed results. This study aims to systematically review and summarize the current evidence on this link.

METHODS AND RESULTS

PubMed, EMBASE, PsycInfo, and Web of Science were searched from 2000 to 2023 without language restriction. Cross-sectional and prospective cohort studies as well as postmortem studies were included. Studies containing data on the link between ICAD, defined as at least 50% stenosis in 1 intracranial vessel, and cognitive impairment and dementia were screened by 2 independent reviewers. A total of 22 (17 observational and 5 postmortem) unique studies, comprising 11 184 individuals (average age range, 59.8-87.6 years; 45.7% women; 36.5% Asian race), were included in the systematic review. Seven of 10 cross-sectional studies and 5 of 7 prospective studies showed a significant association between ICAD and cognitive impairment. In the pooled analysis, ICAD was associated with greater cognitive impairment (measure of association, 1.87 [95% CI, 1.49-2.35]). Meta-regression analyses did not show a significant impact of age, sex, and race. All postmortem studies showed that patients with Alzheimer disease and vascular dementia had a higher burden of ICAD compared with controls.

CONCLUSIONS

This study shows that ICAD is associated with cognitive impairment and dementia across age, sex, and race groups. Our findings may underscore the need to develop individualized dementia preventive care plans in patients with ICAD.

The correlation between medial pattern of intracranial arterial calcification and white matter hyperintensities

BACKGROUND AND AIMS

Despite reported correlations between intracranial arterial calcification (IAC) and white matter hyperintensities (WMH), little is known about the relationship between IAC pattern and WMH. By differentiating intimal and medial IAC, we aimed to investigate the relationship between IAC pattern and WMH.

METHODS

Consecutive acute stroke patients were included. IAC pattern was categorized as intimal or medial on plain brain CT. The number of cerebral arteries involved by IAC for each patient was recorded. IAC severity was defined as focal or diffuse. On brain MRI, the burden of WMH was visually graded and classified as absent mild, moderate and severe. Multiple logistic regression was performed to examine the relationship between IAC and WMH.

RESULTS

Among 265 patients, intimal IAC was detected in 54.7% patients and medial IAC in 48.5% patients. Diffuse IAC was present in 27.9% patients, all of which were medial. WMH was found in 75.5% patients, including 39.6% patients with mild WMH, 26.0% with moderate WMH, and 9.8% with severe WMH. The severity of medial IAC was correlated with WMH occurrence (p < 0.001). Chi-square linear trend suggested the number of arteries involved by medial IAC (p < 0.001) and the severity of medial IAC (p < 0.001) were correlated with WMH burden. Multiple ordinal logistic regression demonstrated a positive correlation of WMH burden with the number of arteries involved by medial IAC (p < 0.001) and the severity of medial IAC (p < 0.001).

CONCLUSIONS

Medial IAC was correlated with WMH. The dose-effect relationship between medial IAC and WMH suggests underlying shared mechanisms of intracranial large artery disease and small vessel disease.

Arterial Calcification and Its Association With Stroke: Implication of Risk, Prognosis, Treatment Response, and Prevention

Stroke is a leading cause of death worldwide. Vascular calcification (VC), defined as deposition of calcium-phosphate complexes in the vessels, is considered as the characteristic of vascular aging. Calcifications at different vessel layers have different implications. Intimal calcification is closely related to atherosclerosis and affects plaque stability, while medial calcification can cause arterial stiffening and reduce compliance. Accumulating evidence suggested that arterial calcifications, including calcifications in the intracranial artery, coronary artery, and carotid artery, are associated with the risk, prognosis, and treatment response of stroke. VC can not only serve as a marker of atherosclerosis, but cause cerebral hemodynamic impairment. In addition, calcifications in large arteries are associated with cerebral small vessel disease. In this review, we summarize the findings of recently published studies focusing on the relationship between large artery calcification and the risk, prognosis, treatment response, and prevention of stroke and also discuss possible mechanisms behind those associations.